fix(ci): correct Railway CLI invocation in GitHub Actions

The deployment was failing because the workflow used incorrect syntax
with `uses: docker://` which caused Docker to misinterpret `up` as an
executable rather than an argument to the Railway CLI.

Split deployment into a separate job using `container:` at the job level,
allowing the Railway CLI to execute properly. This follows Railway's
official documentation for GitHub Actions integration.

.github/workflows/deploy.yaml

@@ -120,10 +120,14 @@ jobs:
       - name: Wait for registry propagation
         run: sleep 5
 
-      # Deploy to Railway
-      - name: Deploy to Railway
-        uses: docker://ghcr.io/railwayapp/cli:latest
+  # Deploy to Railway - separate job to use container properly
+  deploy:
+    name: Deploy to Railway
+    runs-on: ubuntu-latest
+    needs: build-and-deploy
+    container: ghcr.io/railwayapp/cli:latest
     env:
       RAILWAY_TOKEN: ${{ secrets.RAILWAY_TOKEN }}
-        with:
-          args: up --service pac-man
+    steps:
+      - name: Deploy to Railway
+        run: railway up --service pac-man